Thoughtful adventures in the operating system

I can usually type faster in the terminal than doing mouse click on a gui calculator, so I created this scipt to be able to do it quickly from the terminal. There are alot of command line calculators out there so use the one you are comfortable with but I like using bc because of the syntax. For example, you can type:

calc "6/(3*10)"

or something more complex:

calc "8^2*(10/2+(13.2032565*2030)/.349548)" 100

100 is optional, it will specify how many decimals you want to carry it out to (the default is 4).

I’ve been reinstalling my system as of late (been way too along a comin’) and I realized that I hadn’t set up a firewall yet. This, in turn, had me think how many ports were open. I was up too late and probably had too many cokes by then. I had given myself a dead simple root password so that I could finish the install and began getting that tightening, turning, wretching in the belly feeling. I couldn’t help thinking that, “This could be the time that some random joe comes along and finds a nice open gate”. Doesn’t make much sense now, but decided then to build a script that toggles a 20 character random password to relieved my paranoia. Here it is for anyone who can find use of it. Oh, and I did get my install done.

While doing HTML work I tend to do my work with text editors. For this, I use Arachnophilia a Java HTML editor with easy, editable, customizable tags (Review here).

Arachnophilia has support to convert characters to HTML entities but isn’t easy to get to (HTML > More Functions > Char to Entity. There are various web sites that do but if willing to use the terminal they can be quickly gotten there as well. Thanks to script by Darren this can be done easily. It requires script Perls’ HTML::Entities module to do so (for help installing Perl modules look at this page). You’ll probably need redirect the script to point to the Perl program proper:

whereis perl

More than likely its in /usr/bin/perl. After fixing that run the script. This will put you in a sub-shell that you can copy and paste characters to be encoded:

You can also convert a whole file. This will print to standard output (terminal text):

Getting down to watching you favorite movie on your computer? Start the movie, sit down, grab your snack and ten or so minutes later the screen goes blank. This happens in Linux because the desktop has built-in defaults for display power management (DPMS) and screensaving. Timeout settings can vary from distribution to distribution but they all got them. Here’s a basic script that can toggle DPMS and screensaving on and off.

Xorg Server Settings

You can set the values of blank, standby, suspend, and off in the the xorg server configuration file. The defaults are: 15, 20, 30, and 40 minutes. Personally I like to set these to better match how I use my computer:

Section "Monitor"Identifier"Monitor0"Option"DPMS""true"# display power management on (true/false)EndSectionSection "ServerFlags"Option"BlankTime""13"# LED still on, no + (0 disables)Option"StandbyTime""15"# turns off LEDOption"SuspendTime""0"# turns off LED, and most powerOption"OffTime""50"# turns off all powerEndSection

BlankTime is just a cheap screensaver and only real use for me is to tell me that I forgot to disable dpms while watching a movie. Doing this saves me a few seconds that StandbyTime requires to turn on the display again. SuspendTime and StandbyTime are nearly the same thing so I don’t bother setting SuspendTime.

Movietime

Here’s movietime. Movietime should work with just about any type of desktop environment (at least any system with dbus installed which really all of them do). If you aren’t familiar with having your own scripts and how to run them, take a look at this page).

These two scripts will respectively: find if a program is running, and strip-comments from text files. The first is useful if you need to see if the program is running or if you need to kill the process with it’s id, comment strip is a good tool to use if posting configurations on forums as often developers or advanced users already know what the settings actually do.

These two scripts are two different find commands. The first (grok) will list all files in a directory recursively that contain a matched string; the second will locate a file/folder and the change to it’s directory. Neither of these are mine (though slightly edited), I’ve gotten them from the Arch forums where they have a great thread called Post your handy self made command line utilities.

Here are two scripts: one, that helps improve gaming performance, and the other to free up the terminal. I’ve talked about the later before, but I got a new trick up my sleeve. However, before I go any further, I’d like to point out how to use bash scripts so that they are easily accessible, yet (at the same time) out of the way.

Organization

I like to keep my bash scripts out of plain view. Some people like to put their bash scripts in a folder called scripts in their home folder. This works good but keeping the home folder just for documents can help reduce clutter:

Think about putting your scripts in a hidden directory in your home folder. For example, I use a folder called ~/.bin. To make the scripts executable anywhere, create a path to them in your ~/.bashrc:

export PATH="/home/gen2ly/.bin:$PATH

To quickly enter the script directory, you might want to create an alias to it:

alias cdb="cd /home/gen2ly/.bin && ls -h"

Now, reload the bash environment:

source ~/.bashrc

To get to your script directory you can now just do:

After you create a script or download one, it will need to be made executable. You can do this by:

chmod +x script-name

NewX

A basic script but useful for gamers that don’t have the most powerful graphic cards. Compositing can zap game performance pretty thoroughly. Rather than digging through menus and disable compositing this command will just start a new xorg server:

#!/bin/bashDISPLAY=:1.0
xinit $* -- :1

By typing newx a new xorg server will be opened on the eighth virtual console (Ctl+Alt+F8). This will also open a terminal where commands can be entered. Typing exit will exit the new xorg server and return you to your original. Alternatively you can type newx urbanterror and urbanterror will be loaded.

Bgcmd

bgcmd will background a program so that it doesn’t overtake the terminal. I’ve written about this before but I’ve discovered how to add bash-completion to it. I’ve updated the page to reflect such:

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Welcome

Here is a gathering place to share common bits of Linux knowledge. Learning with the operating system is a hobby for me. I enjoy getting along with people and being part of something everyone can contribute to. Comments, tips all liked.

If desired you can learn more about me or view the number of scripts I've wrote.